1. Field of the Invention
The present invention relates to a distance measuring apparatus for camera or the like.
2. Background Information
Heretofore, there have been proposed various so-called active type measuring apparatuses which use a light projecting element and a light receiving element. One such apparatus is shown in FIG. 14 and calculates the distance to an object to be photographed by activating a light emitting element to emit light, receiving the light reflected by the object by a light receiving element, amplifying two signal currents output by the light receiving element by way of separate amplifying circuits having the same circuit construction, subsequently integrating the two signals by two integrating circuits having the same circuit construction and measuring the frequency of light projection or duration of light projection until the integrated voltage exceeds a predetermined voltage.
However, since the distance measuring apparatus shown in FIG. 14 has a plurality of processing systems for the output signals of the light receiving element, such an apparatus exhibits a circuit imbalance due to a difference in the characteristics of individual circuit elements even when the same amplifying circuits and integrating circuits are used. This difference affects the results of distance measurements, thereby generating errors in distance measurement.